Control devices for apparatus for applying coatings to metal sheets



July 14, 1959 A. STUCHBERY 2,894,481

CONTROL DEVICES FOR APPARATUS FOR APPLYING COATINGS T0 METAL SHEETS 4 Sheets-Sheet 1 Filed Jurie 25, 1954 k I Inuenlor I Arih zzr Iaflze Jiackfiery. y a; a Attot neyj y 1959 A. L. STUCHBERY 2,894,481

CONTROL DEVICES FOR APPARATUS FOR APPLYING COATINGS TO METAL SHEETS Filed June 25, 1954 4 Sheets-Sheet 2 Inventor AltomeyJ 2,894,481 CONTROL DEVICES FOR APPARATUS FOR APPLYING COATINGS TO METAL SHEETS Filed June 25. 1954 A. L. STUCHBERY July 14, 959

4 Sheets-Sheet 5 S S In enlor ArZkzzr ZesZie Jiacizfiei'y By I 7 4mm July 14. 1 A. STUCHBERY 2,894,481

CONTROL DEVICES FOR APPARATUS FOR APPLYING commas TO METAL SHEETS Filed J ne 25. 1954 4 Sheets-:Sheet 4 Inventor United States Patent CONTROL DEVICES FOR APPARATUS FOR AP- PLYING COATINGS TO METAL SHEETS Arthur Leslie Stuchbery, Enfield, England, assignor to The Metal Box Company, Limited, London, England, a British company Application June 25, 1954, Serial No. 439,304

Claims priority, application Great Britain June 26, 1953 12 Claims. (Cl. 118-1) This invention relates to control mechanism for machines for printing or applying a coating of lacquer or other liquid to sheets particularly metal sheets.

In a machine for applying a coating of lacquer or other liquid to metal sheets (hereinafter described as a machine of the kind referred to) the metal sheets are successively fed to a pair of rollers between which they pass to receive on the one side of the sheet a coating of lacquer or the like, one of the pair of rollers, e.g. the upper roller, being the impression roller and being formed with a surface which is embossed or otherwise formed to provide the pattern which it is desired to apply to the metal sheet. A thin layer of the lacquer, of a predetermined thickness is continuously applied to the impression roller and the pressure to effect transfer of the lacquer to the sheet is produced by the lower or pressure roller which is adjusted to exert a predetermined pressure against the impression roller as the metal sheets pass between the pair of rollers.

It will be understood that if a metal sheet is not pass ing between the impression and pressure rollers the lacquer or other liquid on the impression roller will be applied to the pressure roller. This is obviously undesirable as the lacquer, if not removed, will then be applied to the reverse side of the next sheet passed between the pair of rollers.

Although the lacquer so applied to the pressure roller could be removed by means of a doctor blade this would inevitably result in wastage of lacquer. Moreover, as the cleaning action of a doctor blade is not perfect, small deposits of lacquer will be left on the pressure roller and if allowed to remain will contaminate the backs of subsequent sheets passing between the rollers.

It will be understood that the impression roller has in its surface a recessed portion extending across the full Width of the roller, and providing an interval between successive applications of lacquer or the like to the sheets, and that the means for feeding the sheets is arranged so that the sheets are fed to the roller as a regular succession, the spacing between successive sheets being equal to the portion of the circumference of the impression roller which is recessed. The sheets are also fed in timed relationship with the rotation of the impression roller so that the lacquer shall be applied to the sheets between the ends thereof, in proper register.

A main object of the present invention is to provide means whereby, in a machine of the kind referred to, the adjustment of the impression and pressure rollers may be controlled so that, when no sheet is passing therebetween the rollers are opened, i.e. spaced from each other to prevent the application of lacquer to the pressure roller, but when a sheet or a normally spaced succession of sheets starts to pass between the pair of rollers in correct time relation therewith, the rollers are closed, i.e. urged together with the required pressure, so that an application of lacquer is made on one side of the sheet in proper register thereon. A further object is to provide similar means'whereby ice the applicator rolls, i.e. the rolls which transfer the lacquer or coating liquid from a feed duct to the main applying roll, can also be tripped out of engagement when the pressure rollers previously referred to are opened. The timing of the movement of these applicator rolls in relation to the main pressure roll will, of course, depend on their disposition relative to the feed line of the sheet.

According to the invention there is provided a device for controlling the opening and closing of rollers in machines of the kind referred to wherein the movement of the rollers to an open or closed position is effected by mechanism operated by a power source which is independent of the drive of the machine, and the actuation of said mechanism to open or close the rollers is determined by the position of a detector member movable in re- 1 spouse to the passage thereover of a sheet, the position of said detector member determining the position, relative to a control member for said independently operated mechanism, of an actuating member adapted to move in timed relationship with the rollers and the sheet and arranged so as in one position, corresponding to the passage of a sheet or a normally spaced succession of sheets, to move said control to effect movement of said rollers to the closed position, and in another position, corresponding to an interruption in the passage of a sheet or of a normally spaced succession of sheets, to move said control to effect movement of said rollers to the open position.

It is preferred according to the invention to employ fluid pressure, conveniently compressed air, to operate the mechanism for opening and closing the rollers and to control the operation of the mechanism by means of a valve member, which is arranged for movement by said actuating member to one of two positions, and controls the application of pressure fluid to one end or the other of a double acting piston in a cylinder, the piston being arranged so as to effect the opening or closing of the rollers, depending on its direction of movement.

The detector member is preferably a lever or finger pivoted and balanced so that it is normally held in a raised position, the finger being arranged so that it will be depressed by the passage thereover of a sheet, or a succession of sheets. The finger is so arranged and constructed that it cannot rise during the interval provided by a succession of sheets fed in the normal manner through the machine.

The other end of the detector finger, by engagement with or disengagement from one of a system of levers, determines the position of an actuating member moving in timed relation with the sheets and the rollers, the actuating member being arranged so that in one position it will operate said valve to elfect opening of the rollers, and in the other position it will operate the valve to elfect closing of said rollers.

In order that the invention may be better understood a preferred embodiment thereof, as applied to a machine of the kind referred to, will now be described by way of example with reference to the accompanying drawings in which, i

Fig. 1 is a longitudinal sectional view of the apparatus according to the invention,

Fig. 2 shown to a larger scale a detail of a detector finger and associated mechanism shown in Fig. 1,

Fig. 3 is an elevation, seen from the other side of the apparatus shown in Fig. 1 of a part of a cam lever shown in Fig. l and an associated valve and control mechanism therefor,

Fig. 4 is a vertical cross sectional view showing a pair of rollers, the opening and closing of which is controlled by the apparatus accordingv to the invention, and the means for actuating the rollers, .1

Fig. is a diagrammatic longitudinal sectional representation of the apparatus shown in Fig. l and Fig. 6 is an end elevation, seen from the left of Fig. 1, showing the incorporation of a duplicate set of control members.

In the following description of the construction and operation of the apparatus according to the invention it will be convenient to refer to Fig. 5 in conjunction with Fig. 1, Fig. 5 showing diagrammatically only the essential features of the apparatus according to the invention.

A machine of the kind referred to, embodying the apparatus according to the invention, comprises essentially a frame 1 in which are arranged an impression roller 2 and a pressure roller 3 through which the metal sheets are fed, by means of a conveyor 4, in timed relationship with the rotation of the rollers 2, 3. In the path of each sheet, as it is fed towards the rollers in the direction indicated by the arrow, there is arranged a detector finger 5, fixed on a body 5:: mounted on a pivot pin 6, the body 5a being weighted so that the detector finger 5 is normally raised above the level of the path of movement of the metal sheets.

Mounted within the machine frame 1 and rotating in timed relationship with the said rollers 2, 3 is a cam shaft 7 carrying a cam 8, the edge of which is engaged by a cam roller 9 mounted at one end of a cam lever 10, the other end of which is connected to a link mechanism to be described hereafter.

The cam lever 10 is conveniently substantially triangular in shape and is pivoted at a point intermediate the ends of its base on a fixed shaft 11, secured in the frame 1. To the apex of the triangular cam lever 10 there is pivotally connected one end of a rod 12 (adjustable in length by means of a turnbuckle 13), to the other end of which is secured a yoke 14 carrying on its forked end a hinge pin 15 on which is pivotally mounted one end of a pawl 16. The pawl 16 is also pivotally mounted, intermediate its free end and its point of attachment to the hinge pin 15, on a fixed spindle 17 secured in a side plate 18 of the frame 1, and the upper end of the pawl 16 is formed with an aperture or window 19 of a shape and size to receive the end 26 of the detector finger body 5a. The arrangement is such that when the detector finger 5 is in the raised position, the said aperture 19 clears the end 20 of the body 5a of the detector finger, the apertured end of the pawl 16 engaging freely about the end 20 of the body 5a as the pawl 16 is pivoted anti- .clockwise about its spindle 17 as shown in dotted lines in Fig. 2. If however, the detector finger 5 is depressed, the end 20 of the detector finger body 5a is raised and will act as a latch and prevent movement of the pawl 16 about its spindle 17 in such direction, the aperture 19 in such position being unable to receive the raised end 211 of the detector finger body 5a.

The downward movement of the detector finger body 50 about the pivot pin 6 is limited by a stop pin 21 engaging a recess in the lower edge of the detector finger body 5a and its upward movement is limited by a further stop pin 22 which is abutted by the upper edge of the detector finger body 5a.

The arrangement of the said triangular lever 10 and the rod 12 connecting the apex thereof to the said pawl 16 is such that when the body 5a of the detector finger 5 is raised by the depression of the detector finger 5, the abutment thus presented to the pivoting pawl 16 causes the said triangular lever 10 to be held in a position in which the cam follower 9 cannot drop off the peak of the earn 8 during rotation of the latter with the said cam shaft 7 and dwell in the lower position of the cam track. When however, the detector finger 5 is in the raised position and the detector finger body 5a is depressed so that the aperture 19 in the said pawl 16 freely receives the end-20v of the detector finger body 5a, .the said cam lever 10 can pivot about shaft 11 as the roller 9'fol1ows the said cam 8.

The end of the said triangular lever 10 opposite to that bearing the said cam follower 9 is pivotally connected by means of the link means 23, 24, 25 to the end of a lever 26 secured on a shaft 27 supported in the frame 1 and by means of a further lever 28 (also secured on shaft 27), and a link 29, pivoted at one end to the free end of lever 28, is linked to a slide 30 to which the other end. of link 29 is pivoted. The slide 30 is mounted to slide on a slide block 31 pivotally mounted on the cam shaft 7 in the machine frame 1. Also secured on shaft 27 is a further lever 32 to the end of which is bolted a fork 33 to which is pivotally connected one end of a spring 34 the other end of which is anchored to a hook 35 mounted on the frame 1. The spring 34 tends to rotate the shaft 27 so that, through the link means 23, 24, 25 and lever 26 the triangular lever 10 is urged to follow with its cam follower 9 the edge of the cam 8, and the slide 30, through lever 28 and link 29 is urged to pivot anticlockwise, as seen in the drawing, about the shaft 7 on which the *block'31 of the slide is pivoted.

The slide 30 is urged to its retracted position by means of a spring 36, one end of which is secured to a bridge 37 secured to the end of the slide 30 and the other end of which is anchored to a hook 38 mounted on the machine frame 1. p

The slide is reciprocated, by means of a further cam 39 secured on said cam shaft 7 and engaged by a cam fol lower 40 mounted on the slide 30, in timed relation with the travel of the sheets and the rotation of the rollers 2, 3.

At the end of the slide 30 remote from the spring 36, the slide carries a yoke 41, the two vertically spaced ends 42, 43 of which respectively carry abutment members 44; 45 each of which is adapted, upon reciprocation of the slide 30 in one angular position thereof about the shaft 7, to abut a similar abutment member 46 or 47 provided one on each of the arms of a double armed lever 48 keyed on a further shaft 49 in the machine frame 1'. Also secured on shaft 49 is a lever arm 50 having a pivoted link 51 and a coupling member 52 connected thereto, said member 52 being connected (Fig. 3) to a valve member 53 of a valve 54, which upon movement of member 53 in one direction or the other by the said lever 50 and the link and coupling members 51, 52 admits compressed air to one side or the other of a double-acting piston 55 (Fig. 4) in a cylinder 56, pivotally mounted on the machine frame. The piston 55 has a piston rod 57 which is pivotally connected by a fork 58 to a lever 59 keyed to a shaft 60 mounted transversely in the ma chine frame below the impression and pressure rollers 2, 3. At each end of shaft 60'there is also keyed thereon a toggle lever 61 to which is pivoted a further toggle lever 62 which in turn is pivotally connected to a slide block 63 arranged for limited vertical movement in a guide 64 in the members of the frame 1. between which'the rollers 2, 3 are mounted. The roller 3 is journalled in the slide blocks 63 and upon movement of piston 55 in one direction or the other the toggle levers 61, 62 will be actuated to effect vertical movement of the blocks 63 and, accord ingly of roller 3 relative to roller 2 to bring the said rollers into or out of contact. Stop members 65, 66 limit movement of the toggle levers 61 in either direction of movement thereof.

The position of the slide 30 and the slide block 31 about the shaft 7 of the latter is determined by the position of the said triangular cam lever 10 connected to the slide 30 through the aforesaid system of link means 23, 24, 25, levers 26 and 28 and link 29.

The angular position of the said cam lever 10 about its shaft 11 is, as previously stated, determined by the position of the detector finger 5 the body 5a of which in the depressed position of finger 5 is engaged by the pawl 16 linked to the said'carn lever 10.

Thus the detector finger 5, byits engagement wither clearance of the pawl 16, determines whichend-of the lever 48 controlling the saidvalvemember 53 is engaged by the yoke 41 carried by the slide 30. It will be seen therefore that the position of the detector finger 5, depending on whether or not a metal sheet is being fed towards the rollers 2, 3, determines whether or not the said rollers are opened or closed by the operation of valve member 53.

A supply of compressed air from any suitable source is connected to valve 54 through a flexible pipe 67 and the valve is connected by way of flexible pipes 68, 69 to each side of the double acting piston 55 in cylinder 56, the movement of the valve member 53 in one direction or the other efiiecting the admission of compressed air to one side of the piston 55 and permitting the discharge of air from the cylinder 56 at the other side of the piston, through exhaust ports (not shown).

The said detector finger 5 is so shaped and arranged that the normal gap between the successive sheets S (Fig. 5 as they are fed towards the rollers 2, 3 does not permit the finger 5 to rise, and the arrangement described is such that the passage of a normal succession of metal sheets S towards the rollers 2, 3 will maintain the rollers 2, 3 in the closed position. When the interval between two successive sheets S is greater than that normally provided, so that the impression roller 3 would transfer lacquer to the pressure roller 2 if the rollers were not opened, the detector finger 5 rises and the compressed air system is thereby caused to operate to open the said rollers 2, 3 and prevent the application of lacquer to the pressure roller 2. In the operation of the machine with the control device according to the invention, assuming that no metal sheets are being fed to the rollers, the rollers must be in the open condition. This is achieved in the following manner.

The detector finger 5 is in the raised position, with the detector finger body 5a depressed. The cam 8, rotating in timed relation with the sheet feeding mechanism and the rollers 2, 3, lifts the cam roller 9 of the triangular cam lever 10 once during each rotation of the cam 8. This causes the pawl 16 to rock about its pivot pin 17, and as the detector finger body 5a is depressed, the aperture 19 in the pawl 16 clears the end 20 of the detector finger body 5a. Accordingly, the said roller 9 of the cam lever 10 can be lifted and dropped ofi' the peak of the cam 8 as the cam 8 rotates, thereby rocking lever 10 about its pivot 11.

During each rotation of the cam 8 the slide 30 is reciprocated, by the cam 39 acting on roller 40, towards and away from the double armed lever 48 linked to the valve member 53 of valve 54 controlling the supply of compressed air to the cylinder 56, the piston 55 of which moves the rollers 2, 3 to the open or closed condition.

When the cam lever 10 pivots as its roller 9 drops off the peak of the cam 8 the slide 30 is rocked about shaft 7 by the action of the link means 23, 24, and levers 26, 28, 29 connecting the slide 30 to the cam lever 10, so as to bring the abutment 45 of the yoke 41 on the slide 30 into a position to engage the abutment 47 of the double armed lever 48 controlling thevalve member 53, the arm 47 being that which, when moved, will cause compressed air to be delivered to the cylinder 56 to move piston 55 in a direction to effect, through toggle levers 61, 62 the movement of the rollers 2, 3 to the open condition. See the dot and dash line position illustrated in Figure 1. When the slide 30 is then reciprocated by cam 39 the said abutment 45 of the yoke 41 abuts the said abutment 47 of the double armed valve control lever 48 to eifect such movement thereof and the opening of the rollers 2, 3.

If, during the next rotation of the cams 8 and 39 there is still no sheet being fed, the same series of operations will be carried out, but in this case the said abutment 45 of the yoke 41 will not move the abutment 47 of the double armed lever 48 as the lever 48 was rocked by the previous engagement of the yoke abutment 45 with abutment 47, and the rollers will thus remain opened.

The movements of the members of the control device are correlated so that, in the operation described above, the rollers will be opened before the coated portion of the impression roller 3 can engage and coat the pressure roller 2, it being understood that a portion of the periphery of the impression roller extending over the full Width thereof is recessed and not supplied with the lacquer or other material to be applied to the sheets S.

If a sheet S is: now fed to the machine the detector finger 5 is depressed and the detector finger body 5a raised. Accordingly the pawl 16, when it is rocked in one direction about its pivot 17, abuts the end 20 of the detector finger body 5a and cannot complete its movement in that direction. As a result, the roller 9 of the cam lever 10 linked to the pawl is prevented from. dropping ofi the peak of the cam and as a consequence lever 10 does not rock about its pivot 11 and the slide 30 will not be rocked about shaft 7 before reciprocation.

Therefore, when the slide 30 is reciprocated, the other abutment 44 of its yoke 41 will be in a position to engage the other abutment 46 of the double armed lever 48 controlling the valve 54 of the compressed air system, this abutment 46 of the lever 48 having been brought into position for engagement by the abutment 44 of the yoke 41 when the double armed lever 48 was pivoted about its shaft 49 by the previous engagement between the yoke abutment 45 and the lever abutment 47.

This movement of the double armed lever 48, in the opposite direction to that previously carried out, effects movement of the control valve member 53 to a position to cause movement of the rollers, 2, 3 towards each other, such movement being correlated with the feed of a sheet S so that the application of lacquer or the like thereto is in correct register on the sheet.

The last described position of the control valve member 53 will continue, so long as a succession of normally spaced sheets S is fed to the rollers 2, 3 but upon the normal interval between the sheets being exceeded, or the sheet feed being stopped, the first described seqilence of operations, to open the rollers 2, 3 will take p ace.

Figure 6 of the drawings show the disposition, transversely of the machine, of parts of the apparatus shown in Figure 1 and also shows the provision of a duplicate set of controls comprising the slide 30 and the linkage therefor operated by the cam lever 10, the valve control lever 48, the valve member 53 and valve 54 and the associates linkage between the valve control lever 48 and the valve.

Such a duplicate set of controls, operated by the single cam lever 10 may be employed to effect the opening and closing of a further set of rollers in the machine, for example, the rolls which transfer the lacquer or coating liquid from a feed duct to the main applying roll. It will be understood that the cam 39 controlling the additional slide 30 will be adjusted so as to give the necessary time interval between the actuation of one set of rolls and the other, as required by the disposition of the respective rolls assemblies relative to the feed line of the sheets fed to the machine.

I claim: 1

1. In apparatus of the character described and includmg cooperative rollerssubject to being opened and closed; devices for controlling the opening and closing of said rollers, the movement of the rollers to an open or closed position being effected by mechanism operated by a power source which is independent of the drive of the machine, and the actuation of said mechanism to open or close the rollers being determined by the position of a detector member movable in response to the passage thereover and contact therewith of a sheet, the position of said detector member determining the position, rel-at1ve to a control member for said independently operated mechanism, an actuating member, means for mov- 7 mg the actuating member continuously and in a regular path and in timed relationship with the rollers and the sheet and said actuating member also being shiftable as to position and arranged so as in one position, corresponding to the passage of a sheet or a predetermined regular succession of sheets, to movesaid control member to effect movement of said rollers to the closed position, and in another position, corresponding to an interruption in the passage of a sheet or said regular succession of sheets to move said control member to eifect movement of said rollers to the open position.

2. Apparatus according to claim 1 wherein fluid pressure, is used to operate the mechanism for opening and closing the rollers and the operation of said mechanism is in turn controlled by a valve member which is arranged for movement by said actuating member to one of two positions, for applying pressure fluid to one end or the other of a cylinder housing a double acting piston, the piston being arranged so as to efiect the opening or closing of the rollers, depending on its direction of movement.

3. A control deivce according to claim 1, wherein said detector member is a finger pivotally mounted in the machine and balanced so that it is normally held in a raised position, the finger being arranged so as to be depressed upon the passage thereover and contact therewith of a sheet or a normally spaced succession of sheets.

4. A control device according to claim 1 wherein said detector member is a finger pivotally mounted in the machine and balancedso that his normally held in a raised position, the finger being arranged so as to be depressed upon the passage thereower of a sheet or a normally spaced succession of sheets, said finger being constructed and arranged so that it cannot rise during the interval provided between successive sheets fed at the intervals required for the normal operation of the machine, but will rise when such intervals are exceeded.

5. Apparatus according to claim 1 wherein fluid pressure is used to operate the mechanism for opening and closing the rollers and the operation of said mechanism is in turn controlled by a valve member which is arranged for movement by said actuating member to one of two positions for applying pressure fluid to one end or the other of a cylinder housing a double acting piston, the piston being arranged so as to effect the opening or closing of the rollers, depending on its direction of movement, wherein said detector member is a finger pivotally mounted in the machine and balanced so that it is normally held in a raised position, the finger being arranged so as to' be depressed upon the passage thereover of a sheet or a normally spaced succession of sheets, said finger being constructed and arranged so that it cannot rise during the interval provided between successive sheets fed at the intervals required for the normal operation of the machine, but will rise when such intervals are exceeded, the end of the detector finger not engaged by said sheets being adapted, upon depression or lifting of said finger to engage with or disengage from one of a system of levers the movement of which determines the position of said actuating member moving in timed relation with the sheets and the rollers, the actuating member being arranged so that in one position it will operate said valve to effect opening of the rollers, and in the other position elfect closing of said rollers.

6. Apparatus as defined in claim 1, wherein said control member is a double armed lever, the movement of which actuates a valve controlling the admission of pressure fluid to a cylinder housing the double acting piston which effects movement of said rollers to the open or closed position, and said actuating member is reciprocated, in timed relationship, with the rollers and the sheet, for engagement with said control member, and is moved into a position for engagement with one end or the other at said controlmember in accordance with the depres- 'sion or lifting ofsaid detector member.

7. A control device according to claim 2 wherein said detector member is a finger pivotally' mounted in the machine and balanced so that it is normally held in a raised position, the finger being arranged so as to be depressed upon the passage thereover of a sheet or a normally spaced succession of sheets.

8. In apparatus of the character described, a pair of opposing rollers, means for feeding sheets in processional order into position for passing between said rollers, roller positioning means for bringing the rollers together in sheet contacting cooperative relation when the sheet feeding means is operating to feed sheets in normal processional order and for bringing about a separation of said rollers whenever the feeding means is operating and there is a break of one or more sheets in the procession of sheets being fed, and, control devices for controlling actuation of said roller positioning means and including detector means engageable and displaceable by sheets as they are fed therepast bytsaid feeding means, said control devices including a constantly reciproc'ated actuator reciprocated in timed relation to the roller and sheet feeder action, a control member effective in one position to bring about an operation of the roller positioning means for separating the rollers and in another position to bring about an operation of said roller positioning means to close the rollers, and means under mechanical control of the detector means for placing the actuator to cause it to move the control member to one or the other of said two positions accordingly as sheets are being fed in normal processional order or with a break of one or more sheets in the procession of sheets.

9. In apparatus of the character described, a pair of opposing rollers, means for feeding sheets in proces'sional order into position for passing between said rollers, roller positioning means for bringing the rollers together in sheet contacting cooperative relation when the sheet feeding means is operating to feed sheets in normal processional order and for bringing about a separation of said rollers whenever the feeding means is operating and there is a break of one or more sheets in the procession of sheets being fed, and control devices for controlling actuation of said roller positioning means and including detector means engageable and displaceable by sheets as they are fed therepast by said feeding means, said con trol devices including a constantly reciprocated actuator reciprocated in timed relation to the roller and sheet feeder action, a control member effective in one position to bring about an operation of the roller positioning means for separating the rollers and in another position to bring about an operation of said roller positioning means to close the rollers-,yand means undermechanical control of the detector means for placing the actuator to cause it to move the control member to one or the other of said two positions accordingly as sheets are being fed in normal processionalorder or with a break of one or more sheets in the procession of sheets, said control member being rockable about a center and having two abutments spaced at opposite sides of said center, and said reciprocable actuator having tWo abutments disposed so that when the actuator is placed in one or the other of two positions of placement one of its abutments will be in position for contacting one of the abutments on the control member and the other of its abutments will be in position for moving without contacting the other of the abutments on said control members.

10. In apparatus of the character described, a pair of opposing rollers, means for feeding sheets in proces sional order into position for passing betweensaid rollers, roller positioning means for bringing the rollers together in sheet contacting cooperative relation when the sheet feeding means is operating to feed sheets in normal processional order and for bringing about a separation of said rollers whenever the feeding means is operating and there is a break of one or more sheets in the procession of sheets being fed, and control devices for controlling actuation of said roller positioning means and including detector means engageable and displaceable by sheets as they are fed therepast by said feeding means, said control devices including a constantly reciprocated actuator reciprocated in timed relation to the roller and sheet feeder action, a control member effective in one position to bring about an operation of the roller positioning means for separating the rollers and in another position to bring about an operation of said roller positioning means to close the rollers, and means under mechanical control of the detector means for placing the actuator to cause it to move the control member to one or the other of said two positions accordingly as sheets are being fed in normal processional order or with a break of one or more sheets in the procession of sheets, said last named means including a rockable actuator shifting means, continuously operating means for rocking said shifting means in timed relation to the roller and sheet feeder action, and latching means held in efiective latching position while the detector means is being engaged by sheets being fed to hold the shifting means stationary and released when a break in the procession of fed sheets occurs to allow said shifting means to be engaged and rocked by said rocking means.

11. In apparatus of the character described, a pair of opposing rollers, means for feeding sheets in processional order into position for passing between said rollers, roller positioning means for bringing the rollers together in sheet contacting cooperative relation when the sheet feeding means is operating to feed sheets in normal processional order and for bringing about a separation of said rollers whenever the feeding means is operating and there is a break of one or more sheets in the procession of sheets being fed, and control devices for controlling actuation of said roller positioning means and including detector means engageable and displaceable by sheets as they are fed therepast by said feeding means, said control devices including a constantly reciprocated jfactuator reciprocated in time relation to the roller and "sheet feeder action, a control member efiective in one position to bring about an operation of the roller positioning means for separating the rollers and in another position to bring about an operation of said roller positioning means to close the rollers, and means under mechanical control of the detector means for placing the actuator to cause it to move the control member to one or the other of said two positions accordingly as sheets ar being fed in normal processional order or with a break of one or more sheets in the procession of sheets, said last named means including a rockable actuator shifting means, continuously operating means for rocking said shifting means in timed relation to the roller and sheet feeder action, and latching means held in elfective latching position while the detector means is being engaged by sheets being fed to hold the shifting means stationary and released when a break in the procession of fed sheets occurs to allow said shifting means to be engaged and rocked by said rocking means, said control member being rockable about a center and having two abutments spaced at opposite sides of said center, and said reciprocable actuator having two abutments disposed so that when the actuator is placed in one or the other of two positions of placement a selected one only of its abutments will be in position for contacting one of the abutments on the control member.

12. In apparatus of the character described, a pair of opposing rollers, means for feeding sheets in proces sional order into position for passing between said rollers, roller positioning means for bringing the rollers together in sheet contacting cooperative relation when the sheet feeding means is operating to feed sheets in normal processional order and for bringing about a separation of said rollers whenever the feeding means is operating and there is a break of one or more sheets in the procession of sheets being fed, and control devices for controlling actuation of said roller positioning means and including detector means engageable and displaceable by sheets as they are fed therepast by said feeding means, said roller positioning means including fluid pressure actuated devices controlled by a shiftable valve, and said control devices including an actuator and means for constantly reciprocating the actuator in timed relation to the roller and sheet feeder action, a control member connected with said valve and effective in one positionto bring about an operation of the roller positioning means for separating the rollers and in another position to bring about an operation of said roller positioning means to close the rollers, and means under mechanical control of the detector means for placing the actuator to cause it to move the control member to one or the other of said two positions accordingly as sheets are being fed in normal processional order or with a break of one or more sheets in. the procession of sheets.

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